OS X: Desktop clutter is a distraction, and Shade is a free Mac app that lets you hide it all with one click when it's time to focus. When you need the files, click again to pull the shade up, and when you need room to think, click to pull the shade down and make them vanish.

Just drag an image (like your wallpaper) to the Shade icon in the menubar to hide your icons behind that image while you work. The image will fall down from the top of the screen and hide your desktop icons. Click the icon again and the shade pulls up, revealing your files. Shade doesn't actually move files the way previously mentionedDesktop Tidy does, but it does let you work without seeing the clutter.